package thread;

import com.sun.jmx.snmp.tasks.ThreadService;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/*
* 线程池
* 线程池是线程的管理机制，主要解决两个问题：
* 1：复用线程
* 2：控制线程数量
* */
public class ThreadPoolDemo {
    public static void main(String[] args) {
        ExecutorService threadPool = Executors.newFixedThreadPool(2);
        for (int i = 0;i<5;i++){
            Runnable r = new Runnable() {
                @Override
                public void run() {
                    try {
                        Thread t = Thread.currentThread();
                        System.out.println(t.getName()+":正在执行一个任务...");
                        Thread.sleep(5000);
                        System.out.println(t.getName()+":执行任务完毕");
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            };
            threadPool.execute(r);
        }
        //shutdown()后，线程池处于关闭状态，此时不再接收接任务，等待现有任务都执行完毕后关闭
        //threadPool.shutdown();
        //System.out.println("线程池关闭");
        //shutdownNow()后，线程池会中断内部线程
        threadPool.shutdownNow();
        System.out.println("线程池关闭");
    }
}
